Minorities are disproportionately affected by most sexually transmitted diseases ($TDs). One STD, chlamydia, may result in pelvic inflammatory disease, infertility, ectopic pregnancy, urethdtis, and cervical cancer. Chlamydia infection also signals unprotected sex and is strongly associated with the spread of HIV. Rates of chlamydia infection among American Indians (AIs) nationally have increased 133% from 1997-2001 and chlamydia infection among AIs is 6 times more common than among the US White population. This epidemic of chlamydia infection is of great concern to AI communities not only because it increases the risk of HIV acquisition, but because of the associated potential for rapid transmission of HIV in the population. Although the number of AIs with HIV/AIDS is low, these concerns are not unfounded since Als have experienced a >10-fold increase in HIV/AIDS since 1990. Reducing STD rates requires understanding patterns of acquisition and transmission of chlamydia among both AI men and women. The female predominance in documented Chlamydia infection has been attributed to distinct but related factors: differential use of health services, in part because women have symptoms substantially more often than men, and challenges to effective partner tracing posed by economic, cultural, and geographic constraints. However, effective partner tracing is a criticalcomponent in reducing the burden of chlamydia since it contributes substantially to reducing its prevalence in the population. In this project, we propose to 1) implement a chlamydia screening program for all males, ages 14-35, who present for care at an IHS facility in a Northern Plains reservation; the data from a bdef questionnaire and the test results will be used to estimate the burden of chlamydia infection by age, gender, presence of symptoms, and clinical history, and to determine infection reduction achieved with universal screening; 2) assess the completeness and yield of partner tracing; and 3) examine rates of re-infection using a test-of-cure strategy. We also will blend these epidemiological data with qualitative data gathered from key informants and focus groups about our brief questionnaire and the partner notification process. Our confidential study database will track demographic data, symptoms, partner follow-up, number of partners, laboratory tests results (re-infection status), and treatment. To accomplish these aims, we have brought together an interdisciplinary team of highly respected, experienced, researchers and clinicians. This project promises to provide the information needed to develop the recommendations for community- and clinic-based strategies to improve screening, partner tracing, and treatment.